I have not readily found the answer, is the ffl part the rail or the grip?
I would like to build a 2011ish but haven’t found a clear answer, albeit I am just starting.

On a 1911 its clear. Frame

Jeeze. Of course.

What are 80% serialized now?

What in the fugk are you talking about?

This part

I was not clear in my question- I am looking at building a double stack in 9mm for a target night shooting at our range. I was looking at the above frames but that is not what I see for a double stack frames. The rail is separate from the mag well.

It was not immediately clear which part was the ffl if it was a 100% frame.

No clue what you are asking then.

the picture above is of a 1911 Frame, the Serial numbered part, IE. 'the Gun'....

grips attach to the frame, the magazine slides into the Frame, the 'SLIDE' goes on top......


How about post a picture of what YOU are looking at.

https://www.1911builders.com/wp-content/uploads/2020/04/2011-Gov-Frame-with-slide-catch.jpg

STI type modular. The 80% of those styles are not an FFL item. As far as the grip I doubt it due to I believe Sig offers a modular.

To answer your question, it would be the upper metal part that holds the fire control and slide rails.

I'd guess it's the part 80% done,
The one you have to "machine".